6. Read the following sentences from the text. "One way some states did this was to require everyone to show a driver's license or
other government identification document in order to vote. Fewer black citizens than
white citizens had such documents, so it was a way to prevent many black citizens from
voting. Many protests against voting restrictions on black citizens took place in the
streets of America, especially in Washington DC
Based on the text, what does the word "restriction" mean?
A. something that limits
B. something that expands
C. something that grows
D. something that follows